An "incredibly rare" coin dating back to the third century AD has been dug up by the side of the A14 between Huntingdon and Cambridge.
It depicts the Roman Emperor Ulpius Cornelius Laelianus, who reigned for just two months in 269AD, before he was allegedly executed by his own soldiers.
The find was unearthed during an archaeological dig as part of the A14 road improvements.
Evidence of Laelianus' rule is rare and little is known about him, due to the fact he only had a very short rule, which makes this an important historical find.
It is not thought the coin arrived in Britain until well after his reign had ended.
Speaking about the find, Dr Steve Sherlock, the lead archaeologist for the A14 project, said: "Discoveries of this kind are incredibly rare.
"This is one of many coins that we've found on this exciting project, but to find one where there are only two known from excavations in this country that portray this particular emperor, really is quite significant.
"I look forward to seeing how the analysis of this find along with numerous other Roman remains that we have found on this project help us better understand our past."
Julian Bowsher, coin expert at MOLA Headland Infrastructure, said: "Roman emperors were very keen to mint coins.
"Laelianus reigned for just two months which is barely enough time to do so. However, coins were struck in Mainz, Germania.
"The fact that one of these coins ever reached the shores of Britain, demonstrates remarkable efficiency, and there's every chance that Laelianus had been killed by the time this coin arrived in Cambridgeshire."
Another coin was also dug up at the site, dating back even further - to around 57BC.
It is thought it was probably minted in northern France to support the resistance of Julius Caesar at the time and that the Belgian Ambiani tribe would have sent the coins across the channel to help British Celts resist Roman invasions.
So far, the digs at the A14 during the upgrading of the road have unearthed woolly mammoth remains and evidence of beer brewing.